FMC- Mine Ventilation, Fires, Explosion & Inundation

1 Bar pressure is equivalent to
Options:
1. 1 kPa
2. 10kPa
3. 100 kPa
4. 1000 kPa
5. None of the Options
Correction Answer : Option No.(3)
Question Text:=
Choose the correct statement
Options:
1. Rate of diffusion of gases into air is directly proportional to their densities.
2. Rate of diffusion of gases into air is directly proportional to the square root of their densities.
3. Rate of diffusion of gases into air is inversely proportional to their densities.
4. Rate of diffusion of gases into air is inversely proportional to the square root of their densities.
5. None of the Options
Correction Answer : Option No.(4)

The average concentration of respirable dust in mine atmosphere during each shift, to which person is exposed at any working is shall not exceed _______ Where the free silica in air borne dust is ________ or less.

If any sampling detects respirable dust concentration of 4.6 mg/m3 and free silica content is 4%, then futher sampling should be done within or not exceeding

Options:
1. 6 months
2. 3 months

3. 2 months

4. 1 month

5. 2Weeks

Correction Answer : Option No.(2)

Question Text:

In a longwall face, % of methane at intake and return gates indicate 0.1 % and 0.4 %, air quantity flowing at the face is 1800 m3/ min, production from the face is 1500 TPD, methane emission rate in m3/tonne of coal output is equal to

If the blade angle of the main fan is increased, the pressure developed by the fan

Options:

1. Increases

2. Decreases

3. May increase and decrease

4. Remains unchanged

5. None of the Options

Correction Answer : Option No.(1)

Question Text:

A hard working man consummes 2 X 10-3 m3/ min of oxygen, the required air Q in m 3/ min containing 21% of oxygen needed to be supplied to the working place per minute so as to keep the level of oxygen concentration of exhale air at 19% will be

4. High thermal conductivity and Self heating rate from 40°C to 70°C is 1.5°C/hr i.e. R70 = 1.5°C/hr.
5. None of the Options

Correction Answer : Option No.(3)

Question Text:

When Tâ‚ is absolute temperature at which evaporation of vapour takes place,T2 is absolute temperature at which condensation of vapour takes place, then co-efficient of performance can be expressed as

Options:
1. Tâ‚/(T2-Tâ‚)
2. Tâ‚/T2
3. (T2-Tâ‚)/Tâ‚

4. Tâ‚/(Tâ‚-T2)
5. None of the Options

Correction Answer : Option No.(1)

Question Text:

What is required to be done, to get high head from axial flow fan, keeping its size and speed within reasonable limit ?

Options:

1. Increase in power input

2. Changing the shape

3. Installing another fan in series
4. Increasing no of stages
5. None of the Options

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Correction Answer : Option No.(4)

Question Text:

Eddy loss for fan is significant when____________

Options:

1. fan runs at its full capacity

2. fan operates at low volume

3. fan drift cross-section is very high

4. fan drift cross-section is very low

5. fan operates at high volume

Correction Answer : Option No.(2)

Question Text:

Large ventilation fan with high starting torque preferable motor will be

Options:

1. Squirrel cage Induction Motor

2. Capacitor start Motor

3. DC shunt Motor

4. Slip ring Induction Motor

5. None of the Options

Correction Answer : Option No.(4)

Question Text:
Which statement is correct?

Options:
1. Flammability of coal dust increases in proportion with increase in percentage of fire damp
2. Flammability of coal dust decreases in proportion with increase in percentage of fire damp
3. Flammability of coal dust does not depend on presence of fire damp
4. Flammability of the coal dust initially increases and then decreases
5. None of the Options

Correction Answer : Option No.(1)

Question Text:
The purpose of evassee in a fan is not

Options:

1. To reduce the final velocity of the discharged air by providing a passage of increasing cross section through which air must pass
2. To eliminate turbulence
3. To promote smooth flow of air and prevent re-entry of air from atmosphere
4. To reduce the air quantity
5. To increase fan efficiency

Correction Answer : Option No.(4)

Question Text:

The permission to extract pillars below an area has been obtained. The HFL of the area changes and HFL passes over this area. Under the circumstances what needs to be done.

Options:

1. Extraction can be continued as permitted earleir.

2. Fresh permission from DGMS will be required for extracting pillars.

3. Embankment may be constructed to keep the area unaffected from new HFL

4. Embankment may be constructed to keep the area unaffected from new HFL and fresh permission from DGMS will also be required for extracting pillars.
5. None of the Options

Correction Answer : Option No.(4)

Question Text:
The unit kgf.s².m¯â¸ is also known as

Options:

1. gaul

2. Murg

3. Killomurg

4. Atkinson

5. None of the Options

Correction Answer : Option No.(3)

Question Text:
Mass of water vapour present in a unit mass of air is known as

1. Trickett"s ratio for assessing status of fire in a sealed area will not work, if intake air is oxygen deficient through the injection of nitrogen and carbon dioxide or through a high methane make)
2. Fresh air dilution of the fire products has no effect on Trickett"s ratio.
3. If Trickett"s ratio is less than 0.4, there is no fire and gases are residual than active
4. If Trickett" ratio is > 1.6, there is serious fire

When regulator is installed to regulate air quantity in a district, the pressure developed in the main fan

Options:

1. decreases
2. increases
3. remain same
4. may increase or decrease depending on the fan type
(5) None of the Options

Correction Answer : Option No.(2)

Question Text:

Which is correct statement ?

Options:

1. Foam extinguisher when directed against a fire, the foam spreads over the entire fire area covering or blanketing it, thus cutting oxygen supply.
2. Wet foam layer produces a cooling effect to extinguish the fire.

3. Foam extinguisher when directed against a fire, the foam spreads over the entire fire area covering or blanketing it, thus cutting oxygen supply; and Wet foam layer produces a cooling effect to extinguish the fire.

The auxiliary fan should not suck more than ______% of available air to avoid recirculation.

Options:
1. 30
2. 40
3. 50
4. 60
5. 70

Correction Answer : Option No.(3)

Question Text:

Which is wrong statement ?

Options:
1. Reversing of air current is easier in axial flow fan compared to centrifugal fan.
2. Less space is required in case of axial flow fan compared to centrifugal fan
3. Axial flow fan is used when low air quantity at high pressure is required.
4. Cost of axial flow fan is less compared to centrifugan fan
5. None of the Options

Correction Answer : Option No.(3)

Question Text:
Which of the following is not the advatage of fighting fire with inert gases

Options:

1. It offers maximum possible safety against risk of explosion & spread of fire, if applied at correct time
2. Recovery work negligible & hence rapid

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Question Text:
The operating point of a PV-200 fan is as follows. Quantity =1800m3/min, pressure=10 mm w.g. The mine resistence in kilo murg is equal to
Options:
6. 0.011
7. 0.11
3. 0.278
4. 1.1
5. None of the Options
Correction Answer : Option No.(1)www.onlineminingexam.com
Question Text:
When Q is in m3 / sec and P in Pa and R is in Gaul, Equivalent orifice in m2 can be defined as
Options:
6. 1.29Q/√P
7. 1.29/√R
8. 1.29√P/Q
9. 2.29√P/Q
10. 2.29Q/√P
Correction Answer : Option No.(2)
Question Text:
Which of the following is true?
Options:
11. Q2=R/P
2. Q=√R/P
3. Q=√R/√P
4. Q=√P/√R
5. Q=R/P
Correction Answer : Option No.(4)
Question Text:
If air quantity circulated by the fan is 6000 m3 /min and pressure developed by the fan is 100 Pa, air power is equal to
Options:
6. 10 kW
7. 100 kW
3. 600 kW
4. 700 kW
5. None of the Options
Correction Answer : Option No.(1)
Question Text:
In a sealed off area, the analysis report shows the following gas percentage O2-19.2, CO-0.8, CO2-2, and N2-78 , the Graham's ratio is
Options:
6. 0.04
2. 0.54
3. 0.78
4. 1.36
5. None of the Options
Correction Answer : Option No.(2)
Question Text:
Which statement is most correct?
Options:
6. Coal dust explosion are more severe than methane explosion
2. With methan explosion, CO is occasionally found while in coal dust explosion CO is always found
3. With methane explosion H2S gas is always found
4. Coal dust explosion are more severe and always associated with presence of CO; where as methane explosion comparatively weaker with lesser CO generation
5. None of the Options
Correction Answer : Option No.(4)
Question Text:
Fire extinguishing index is
Options:
6. intensity of inert gas injection rate to reduce oxygen from a level of 21% to 2% in a sealed off area
2. the ratio of total injection of inert gas in m3 to the time in hours it requires to fill the sealed off volume
3. a measure for the fraction of the sealed volume which is filled with inert gases per month
4. a measure for the fraction of the sealed volume which is filled with inert gases per day
5. None of the Options
Correction Answer : Option No.(2)
Question Text:
Minimum velocity required at 4.5m from any discontinued face in degree III mine?
Options:
6. 15 m/ min
7. 30 m/min
8. 45m/min
9. 60m/min
10. None of the Options
Correction Answer : Option No.(3)
Question Text:
When nitrous fumes passes over a filter paper soaked with starch and potassium iodite, the filter paper becomes
Options:
5. red
2. yellow
3. black
4. green
5. blue
Correction Answer : Option No.(5)
Question Text:
The mechanical efficiency of a fan is
Options:
7. the ratio of the power actually absorbed by the impeller and converted into head to the power applied to the shaft
2. the ratio of the air power to the input power
3. the ratio of the input head to Euler's head
4. the ratio of total head developed to the velocity head
5. None of the Options
Correction Answer : Option No.(1)